Release medium for use in the production of abrasion-resistant decorative laminates and a method for the production of abrasion-resistant decorative laminates

Abstract

An improved release medium is disclosed for use in the production of decorative laminates by pressure consolidation. The release medium comprises a self-sustaining release sheet having at least one of its surfaces coated with a composition comprised of mineral particles dispersed in a resinous matrix. The release medium may be used to apply an abrasion-resistant coating to the surface of a decorative laminate during production of the laminate by pressure consolidation.

We claim: 
     
       1. In a method for the production of decorative laminates by pressure consolidation comprising: (a) providing at least one release medium comprised of a self-sustaining release sheet having opposite first and second surfaces;   (b) providing at least one decorative laminate sheet assembly comprised of at least one core sheet and a decorative sheet;   (c) positioning said at least one release medium adjacent said decorative sheet of said at least one decorative laminate sheet assembly; and   (d) forming at least one decorative laminate from said at least one decorative laminate sheet assembly by the application of heat and pressure; the improvement which comprises forming on said at least one release medium on a surface adjacent said decorative sheet a coating of a composition comprised of abrasion-resistant mineral particles dispersed in a resinous matrix by applying a layer of abrasion-resistant mineral particles dispersed in an uncured resinous matrix; and then, curing said matrix to the B-stage whereby an abrasion-resistant coating is formed on the surface of said decorative sheet of said at least one decorative laminate during said application of heat and pressure.   
     
     
       2. The method of claim 1 wherein said self-sustaining release sheet is selected from the group consisting of paper, metallic foil, a paper-metallic foil laminate and a synthetic resin film. 
     
     
       3. The method of claim 1 wherein said release sheet is comprised of a synthetic resin selected from the group consisting of polypropylene, polybutylene and polyethylene terephthalate. 
     
     
       4. The method of claim 1 wherein said release sheet is comprised of a metallic foil. 
     
     
       5. The method of claim 4 wherein said foil is an aluminum foil. 
     
     
       6. The method of claim 2 wherein said release sheet is comprised of a paper-metallic foil laminate. 
     
     
       7. The method of claim 6 wherein said foil laminate is comprised of a paper substrate and outer layers of aluminum foil. 
     
     
       8. The method of claim 1 wherein said abrasion-resistant particles are selected from the group consisting of silica, alumina, alundum, corundum, emery, tungsten carbide, beryllium carbide, silicon carbide, aluminum boride, boron carbide, diamond dust and mixtures thereof. 
     
     
       9. The method of claim 8 wherein said particles comprise alumina particles. 
     
     
       10. The method of claim 1 wherein said particles range in size from about 10 micron average particle size to about 75 micron average particle size. 
     
     
       11. The method of claim 1 wherein said resinous matrix comprises a melamine resin. 
     
     
       12. The method of claim 1 wherein said mineral particles are present in an amount ranging from about 2 to 15 percent by weight based on the weight of the resin.